I've been getting sporadic TMPS sensor light all summer long. The first time it happened I immediatedly filled the tires, but they were already set. I set the pressure at 35psi for all tires.

My going theory is that the heat messes with the sensor, but IDK how the sensor actually works so that's why I'm asking.

Also, thought this might just be a quirk with the car itself? But I doubt it.

Do I really need to unseat the tire to check the sensors? That's what i'm reading in other threads.

Some video said it could be one of the sensors needs its battery changed. I have no idea when or if the battery was ever replaced.

This should really be in "tire and wheel" section.

A tire shop can tell you which sensor is an issue and likely what the issue is. This is with a scanner with the wheel still on the car (for most sensors.)
Yes, some sensors have replaceable batteries. Lots of short trips kill them faster than lots of long trips. The reason for this is when you first start a trip, the car pings the sensors a lot, later they ping them once in a while. Short trips means less time in big lapses of pings.
Yes, to change a battery requires you to pull the wheel, then dismount the tire.

High temperatures can affect the sensor, causing the tire pressure to suddenly increase or decrease and activate the warning light. Another possible cause is that the sensor battery is low, and replacing the battery often involves removing the tire. You can try checking the sensor with a diagnostic tool without removing the tire. If the problem persists, taking the vehicle to a professional repair facility to have the TPMS sensor tested and repaired may be the best solution.

If you find the solution to this problem let me know.

Yes, it would be good for everyone to know what happened instead of a dead end thread.